Extreme weather fueled by climate change hit 4 in 10 Americans where they lived in 2021

Raging wildfires exacerbated by drought in the West; severe downpours across the Midwest, Northeast and South; deadly heat waves in the Pacific Northwest; hurricanes that unleashed destruction from the Gulf Coast up to New England: 2021 was a year when it became impossible for many Americans to ignore the extreme weather fueled by climate change.

More than 4 in 10 U.S. residents live in a county that was affected by those weather disasters this past year, according to an analysis by the Washington Post — and more than 80 percent found themselves sweltering in abnormally high temperatures lasting more than a single day.

In June, when a heat dome descended over the Pacific Northwest, smashing high-temperature records in cities like Portland, Ore., and Seattle, millions of Americans suffered and hundreds died. An estimated 1 billion sea creatures were also killed along the coast of British Columbia, Canada, and endangered salmon populations were basically cooked alive in streams and rivers across the region.

Meanwhile, numerous examples of inundating rainfall across the country overwhelmed infrastructure, flooded basements and subways, left dozens dead, and racked up tens of billions of dollars in insurance losses. The key driver behind the sudden downpours is the fact that for every 1.8°F of warming, the Earth's atmosphere holds 7 percent more moisture. When conditions are right, that moisture is unleashed in the form of rainfall of unprecedented ferocity.

The cause of climate change is, of course, well established. Mankind's relentless pumping of greenhouse gases into the atmosphere since the dawn of the Industrial Revolution has pushed global temperatures higher by 2.2°F. While that may sound like a small amount, the bulk of that warming has happened in recent decades, and its impacts have reverberated across the planet.

In a 2019 report, NASA warned that if average global temperatures were to cross the threshold of 2.7°F (1.5°C) of warming, the consequences would be dire for life on Earth.

"Most land regions will see more hot days, especially in the tropics. At 1.5 degrees Celsius warming, about 14 percent of Earth’s population will be exposed to severe heatwaves at least once every five years, while at 2 degrees warming that number jumps to 37 percent," the report's summary stated. "Extreme heatwaves will become widespread at 1.5 degrees Celsius warming."

Certain parts of the world, such as New England, have already exceeded that mark, and a forecast from the Climate Action Tracker based on the current rate of greenhouse gas emissions and pledges made by nations at the Glasgow climate change conference estimates that the world is on course for as much as 2.6°C of warming by 2100.

As a result, our extreme weather future doesn't look very encouraging. A study published last week in Nature Geoscience found that, thanks to climate change, more hurricanes will be coming to midlatitude regions, which includes population centers like New York and Boston. Efforts to cut greenhouse gas emissions in the U.S. have stalled in the Senate along with President Biden's Build Back Better bill.

While much of the nation has gone from setting temperature records this winter to battling snow and ice this past week, the arrival of winter conditions should not be taken as a sign that the threat from climate change is overblown or that its impacts are exclusively a summertime problem.

Just as the extreme cold snap that hit Texas in early 2021 has been linked to climate change, the frequency of "extreme snowstorms in the eastern two-thirds of the the contiguous United States has increased over the past century," the National Oceanic and Atmospheric Administration states on its website. But thanks to jet stream disruptions linked to climate change, the effects are not uniform.

As the December blaze near Boulder, Colo., showed, climate change effectively primes the planet for extreme weather disasters. The state, which has been in the grips of extreme drought, recording its lowest amount of precipitation on record between July 1 and Dec. 29, was hit with 100-mile-per-hour wind gusts on Dec. 30.

“Everything is kind of crispy,” Keith Musselman, a snow hydrologist and assistant research professor at the University of Colorado Boulder, told NBC News. “In addition to the extreme drought, just 1- or 2-degree warmer days can really dry out the landscape quite a bit more, so everything is that much drier and flammable.”

The wildfires that closed out 2021 in Colorado destroyed nearly 1,000 homes, capping a year in which climate change showed its fangs.